define "Currently pregnant SRV.DE7 Condition":
  [Condition: Concepts."Currently pregnant - HIV.SRV.DE7"]

define "Currently pregnant SRV.DE7 Condition":
  Elements."Currently pregnant SRV.DE7 Condition" C
    where C.prevalenceInterval() overlaps "Measurement Period"

/* End of ART start date SRV.DE6 */

/*
@dataElement: HIV.SRV.DE7 - Currently pregnant
@activity: HIV.B6 Capture or update client history
@description: Client is currently pregnant
*/

define "Currently pregnant SRV.DE7":
  exists "Currently pregnant SRV.DE7 Condition"

/* End of Date informed of HIV-positive diagnosis */

/*
@activity: HIV.B7 Test for HIV using testing algorithm
*/
define "HIV test":
  [Observation: Concepts."HIV test type - HIV.B.DE81 Choices"] O
  where O.status in { 'final', 'amended', 'corrected' }

/* End of HIV test date B.DE110 */

/*
@dataElement: HIV.B.DE111 - HIV test result
@activity: HIV.B7 Test for HIV using testing algorithm
@description: The result from HIV testing after applying the testing algorithm
*/
// Same as test - see profile
define "HIV test result Observation":
  "HIV test" O

// Moved and Redefined in HIE
// define "HIV test resulted":
//   [Observation] O
//     where O.status in {'final', 'amended'}
//     and O.code ~ Concepts."Rapid diagnostic test for HIV - HIV.B.DE82"

/* End of HIV test result B.DE111 */

/*
@dataElement: HIV.B.DE112 - HIV-positive
@activity: HIV.B7 Test for HIV using testing algorithm
@description: Test result is HIV-positive
*/
define "HIV-positive test result":
  "HIV test result Observation" O
    where O.value ~ Concepts."HIV-positive - HIV.B.DE112"

/* End of Other E.DE70 */

/*
@dataElement: HIV.E.DE85 - ANC contact date
@activity: HIV.E1 Capture or update mother's history
@description: The date and time of the client's ANC contact (in the ANC DAK this is called 'Contact date')
*/

define "Antenatal care contact":
  [Encounter] E
    where E.type.coding.code contains ConceptsCustom."Antenatal care contact".code

/* End of Facility-level testing */

/*
@dataElement: HIV.B.DE29 - Currently pregnant
@activity: HIV.B6 Capture or update client history
@description: Client is currently pregnant
*/

define "Currently pregnant B.DE29":
  [Condition: Concepts."Currently pregnant - HIV.B.DE29"] C
  sort by start of prevalenceInterval()

/* End of Facility-level testing */

/*
@dataElement: HIV.B.DE29 - Currently pregnant
@activity: HIV.B6 Capture or update client history
@description: Client is currently pregnant
*/

define "Currently pregnant B.DE29":
  Elements."Currently pregnant B.DE29" C
    where C.prevalenceInterval() during "Measurement Period"

define "ANC within pregnancy dates":
  Elements."Antenatal care contact" E
  where E.period.toInterval() during First("Currently pregnant B.DE29").prevalenceInterval()
  return E.period.toInterval()

define "first anc date":
  First("ANC within pregnancy dates")

/* End of HIV-inconclusive */

/*
@dataElement: HIV.B.DE115 - HIV status
@activity: HIV.B7 Test for HIV using testing algorithm
@description: HIV status reported after applying the national HIV testing algorithm. No single HIV test can provide an HIV-positive diagnosis.
*/
define "HIV Status Observation":
  [Observation: Concepts."HIV status"] O
    where O.status in { 'final', 'amended', 'corrected' }

define "HIV Status Positive Observation":
"HIV Status Observation" O
    where O.value ~ Concepts."HIV-positive - HIV.B.DE116"
      sort by start of effective.toInterval()

define "HIV Status Positive Observation Date":
  "HIV Status Positive Observation" O
  return start of O.effective.toInterval()

define "HIV Status Positive Condition":
  [Condition: Concepts."HIV-positive - HIV.B.DE116"] C
    where C.clinicalStatus ~ ConceptsCustom."active"
      and exists(C.category CC where CC ~ ConceptsCustom."encounter-diagnosis")
    sort by start of onset.toInterval()

define "HIV Status Positive Condition Date":
  "HIV Status Positive Condition" C
  return start of C.onset.toInterval()

/*
@dataElement: HIV.B.DE116 - HIV-positive
@activity: HIV.B7 Test for HIV using testing algorithm
@description: Client is HIV-positive
*/
define "Date HIV Status Positive":
  Min("HIV Status Positive Observation Date" union "HIV Status Positive Condition Date")

/**
 * Numerator
 * 
 * Definition: Number of ANC attendees who tested HIV-positive at their first test during the current pregnancy plus number of ANC attendees known to be HIV-positive before their first ANC visit
 * Calculation: COUNT of "Currently pregnant" clients with "HIV test result"='HIV-positive' AND "HIV test date" on "ANC contact date" is EARLIEST within current pregnancy | PLUS | COUNT of clients with "HIV status"='HIV-positive' on first "ANC contact date"
 */

define "Numerator":
  HIE."Currently pregnant SRV.DE7"
  and exists(HE."HIV-positive test result" O
  where start of O.effective.toInterval() = start of HIE."first anc date"
  ) and HE."Date HIV Status Positive" before start of HIE."first anc date"

/**
 * Denominator
 *
 * Definition: Number of ANC attendees receiving their first HIV test during pregnancy plus number of ANC attendees known to be HIV-positive before first ANC visit
 * Calculation: COUNT of "Currently pregnant" clients with "HIV test date" on a "ANC contact date" during current pregnancy | PLUS | COUNT of clients with "HIV status"='HIV-positive' on first "ANC contact date"
 */

define "Denominator":
  HIE."Currently pregnant SRV.DE7"
  and exists(HE."HIV test" O
  where start of O.effective.toInterval() = start of HIE."first anc date"
  ) and HE."Date HIV Status Positive" before start of HIE."first anc date"

/* Populations */

/*
 *Initial Population
 */

define "Initial Population":
  true

/*
@description: Returns an interval representing the normalized prevalence period of a given Condition resource.
@comment: Uses the toInterval and toAbatementInterval functions to determine the widest potential interval from
onset to abatement as specified in the given Condition.
*/
define fluent function prevalenceInterval(condition Condition):
if condition.clinicalStatus ~ "active"
  or condition.clinicalStatus ~ "recurrence"
  or condition.clinicalStatus ~ "relapse" then
  Interval[start of condition.onset.toInterval(), end of condition.abatementInterval()]
else
  (end of condition.abatementInterval()) abatementDate
    return 
	  if abatementDate is null then
        Interval[start of condition.onset.toInterval(), abatementDate)
      else
        Interval[start of condition.onset.toInterval(), abatementDate]

define function ToConcept(concept FHIR.CodeableConcept):
    if concept is null then
        null
    else
        System.Concept {
            codes: concept.coding C return ToCode(C),
            display: concept.text.value
        }

define function ToCode(coding FHIR.Coding):
    if coding is null then
        null
    else
        System.Code {
          code: coding.code.value,
          system: coding.system.value,
          version: coding.version.value,
          display: coding.display.value
        }

/*
@description: Returns an interval representing the normalized Abatement of a given Condition resource.
@comment: NOTE: Due to the complexity of determining an interval from a String, this function will throw
a run-time exception if used with a Condition instance that has a String as the abatement value.
*/
define fluent function abatementInterval(condition Condition):
  if condition.abatement is FHIR.dateTime then
    Interval[FHIRHelpers.ToDateTime(condition.abatement as FHIR.dateTime), FHIRHelpers.ToDateTime(condition.abatement as FHIR.dateTime)]
  else if condition.abatement is FHIR.Period then
    FHIRHelpers.ToInterval(condition.abatement as FHIR.Period)
  else if condition.abatement is FHIR.string then
    Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a String value is not supported')
  else if condition.abatement is FHIR.Age then
    Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(condition.abatement as FHIR.Age),
      FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(condition.abatement as FHIR.Age) + 1 year)
  else if condition.abatement is FHIR.Range then
    Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((condition.abatement as FHIR.Range).low),
      FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((condition.abatement as FHIR.Range).high) + 1 year)
  else if condition.abatement is FHIR.boolean then
    Interval[end of condition.onset.toInterval(), condition.recordedDate)
  else 
    null

define function ToDateTime(value dateTime): value.value

define function ToInterval(period FHIR.Period):
    if period is null then
        null
    else
        if period."start" is null then
            Interval(period."start".value, period."end".value]
        else
            Interval[period."start".value, period."end".value]

define function ToDate(value date): value.value

define function ToQuantity(quantity FHIR.Quantity):
    case
        when quantity is null then null
        when quantity.value is null then null
        when quantity.comparator is not null then
            Message(null, true, 'FHIRHelpers.ToQuantity.ComparatorQuantityNotSupported', 'Error', 'FHIR Quantity value has a comparator and cannot be converted to a System.Quantity value.')
        when quantity.system is null or quantity.system.value = 'http://unitsofmeasure.org'
              or quantity.system.value = 'http://hl7.org/fhirpath/CodeSystem/calendar-units' then
            System.Quantity { value: quantity.value.value, unit: ToCalendarUnit(Coalesce(quantity.code.value, quantity.unit.value, '1')) }
        else
            Message(null, true, 'FHIRHelpers.ToQuantity.InvalidFHIRQuantity', 'Error', 'Invalid FHIR Quantity code: ' & quantity.unit.value & ' (' & quantity.system.value & '|' & quantity.code.value & ')')
    end

define function ToCalendarUnit(unit System.String):
    case unit
        when 'ms' then 'millisecond'
        when 's' then 'second'
        when 'min' then 'minute'
        when 'h' then 'hour'
        when 'd' then 'day'
        when 'wk' then 'week'
        when 'mo' then 'month'
        when 'a' then 'year'
        else unit
    end

define function ToString(value ObservationStatus): value.value

define function ToString(value string): value.value

/*
From FHIRCommon 4.1.0:
*/

/*
@description: Normalizes a value that is a choice of timing-valued types to an equivalent interval
@comment: Normalizes a choice type of FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instance, FHIR.string, FHIR.Age, or FHIR.Range types
to an equivalent interval. This selection of choice types is a superset of the majority of choice types that are used as possible
representations for timing-valued elements in FHIR, allowing this function to be used across any resource.

The input can be provided as a dateTime, Period, Timing, instant, string, Age, or Range.
The intent of this function is to provide a clear and concise mechanism to treat single
elements that have multiple possible representations as intervals so that logic doesn't have to account
for the variability. More complex calculations (such as medication request period or dispense period
calculation) need specific guidance and consideration. That guidance may make use of this function, but
the focus of this function is on single element calculations where the semantics are unambiguous.
If the input is a dateTime, the result a DateTime Interval beginning and ending on that dateTime.
If the input is a Period, the result is a DateTime Interval.
If the input is a Timing, an error is raised indicating a single interval cannot be computed from a Timing.
If the input is an instant, the result is a DateTime Interval beginning and ending on that instant.
If the input is a string, an error is raised indicating a single interval cannot be computed from a string.
If the input is an Age, the result is a DateTime Interval beginning when the patient was the given Age,
and ending immediately prior to when the patient was the given Age plus one year.
If the input is a Range, the result is a DateTime Interval beginning when the patient was the Age given
by the low end of the Range, and ending immediately prior to when the patient was the Age given by the
high end of the Range plus one year.

NOTE: Due to the
complexity of determining a single interval from a Timing or String type, this function will throw a run-time exception if it is used
with a Timing or String.
*/
define fluent function toInterval(choice Choice<FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instant, FHIR.string, FHIR.Age, FHIR.Range>):
  case
    when choice is FHIR.dateTime then
      Interval[FHIRHelpers.ToDateTime(choice as FHIR.dateTime), FHIRHelpers.ToDateTime(choice as FHIR.dateTime)]
    when choice is FHIR.Period then
      FHIRHelpers.ToInterval(choice as FHIR.Period)
    when choice is FHIR.instant then
      Interval[FHIRHelpers.ToDateTime(choice as FHIR.instant), FHIRHelpers.ToDateTime(choice as FHIR.instant)]
    when choice is FHIR.Age then
      Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age),
        FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age) + 1 year)
    when choice is FHIR.Range then
      Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).low),
        FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).high) + 1 year)
    when choice is FHIR.Timing then
      Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a Timing value is not supported')
    when choice is FHIR.string then
      Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a String value is not supported')
    else
      null as Interval<DateTime>
  end

define function ToDateTime(value instant): value.value